- use schibo audio plugin 1.2, extremly awesome on surround speakers like Gigaworks 750S on Conker's Bad Fur Day (CBFD), Centre Court Tennis or Diddy Kong Racing. Does not work with some games making no sound and/or making the emulation really slow.
When it works for a game, it is far from the best plugin.

- Zilmar audio plugin but the audio accuracy meet many issues.

- The great and best alternative for Realtek HD audio users : Go on Realtek panel and activate a sound environnement like "generic" "room" or another one than suits you. Only activating a sound environment makes surround from audio plugins.
On Windows XP (unlike Windows 7) we get no surround on internet browser also (youtube for exemple), that fix this as well. =)
I advice Azimer's HLE audio or Shunyuan's HLE Audio or Jabo's audio plugin.

After 4 painful days of project 64 configuration, I can tell that 2.1 provide the best emulation with latest GFX plugins. The issues on CBFD are all solved ! (please desactivate the memory caching or the game will crash on PJ64 2.x then it's PERFECT, better than changing CPU core method into interpreter because it slows down a bit the emulation).
About CBFD the [E] and [u] versions does not share the same default rom options.
The [E] rom works as fine as [u] when desactivating "32 Bit Engine".

Actually, the N64 emulation we get thanks to Jabo, Zilmar and plugin builders makes N64 environment totally AMAZING. Thanks to the forum community as well.

- The great and best alternative for Realtek HD audio users : Go on Realtek panel and activate a sound environnement like "generic" "room" or another one than suits you. Only activating a sound environment makes surround from audio plugins.
On Windows XP (unlike Windows 7) we get no surround on internet browser also (youtube for exemple), that fix this as well. =)
I advice Azimer's HLE audio or Shunyuan's HLE Audio or Jabo's audio plugin.

I'm not completely sure, but I think implementing true surround sound which outputs to 5.1 or 7.1 discrete channels would require HLE audio, something which is extraordinarily hard to implement for very little gain. It would be cool, though.